PLANS for hydropower dams along the Mekong River threaten the survival of iconic fish species already considered endangered, according to the conservation group World Wide Fund for Nature (WWF).

In a report released yesterday, the WWF highlights giant fish species that live in the Mekong River, using them as examples of what could be lost if dam plans go forward. The fish, already listed as critically endangered by the International Union for Conservation of Nature, could be driven to extinction if plans proceed on 11 dams proposed by countries around the Lower Mekong, the report says.

Species such as the “car-sized” Mekong giant catfish migrate from the Tonle Sap lake to spawning grounds in Thailand and Laos. Dams will likely obstruct these migration routes, conservationists say.

“No hydropower dam built today is able to handle such a large and diverse fish migration as what the Mekong River has,” WWF-Cambodia country director Teak Seng said.

He warned that Cambodia stands to lose the most from damming the Mekong when compared to its neighbours.

“It is the country the most dependent on wild fisheries for its protein intake. As a downstream country, it will bear a big share of the impacts from hydropower development upstream,” Teak Seng said.

Cambodian officials have said that domestic hydropower is crucial to development in a country with electricity rates that are among the highest in

the region. Still, Long Korn, the chief of the Mekong Fisheries Administration Inspectorate at the Ministry of Agriculture, said authorities are well aware of the environmental risks.

“The government is also worried that if we have many hydropower dams, fish may not be able to migrate from one place to another and it could lead to extinction,” he said. Long Korn said that his ministry is holding a workshop this week to discuss the issue.

Studies by the Mekong River Commission have suggested that dams along the Lower Mekong could have a detrimental impact on fish populations, and that existing technology to mitigate such effects may be insufficient.

An MRC report released last December, which studied the effects of dams on migration in the Lower Mekong, suggested that even a single dam would have negative impacts. Three dams could be fatal to five large species analysed in the study, including the Mekong giant catfish.

“No large species are predicted to persist if three dams have to be crossed or if their reproductive potential is low,” the study stated. “With potentially increasing rates of exploration from a growing basin population and the prospect of multiple dam obstructions, fears surrounding the persistence of [Mekong giant catfish] ... appear warranted.”